The best idea I've stumbled upon lately is IdeaPaint, a water-based product that turns any wall, cabinet front, or even a piece of furniture into a dry-erase surface. IdeaPaint requires only one coat and works with any brand of dry-erase markers.
Above: In a children's room, dry-erase paint is a dust-free alternative to chalkboard paint.
Above: The CRE-8 50-Square-Foot Kit is $175, and the CRE-8 25-Square-Foot Coverage Kit is available in 10 colors for $99.95. For smaller jobs, the Lil' Bit Kit covers three square feet; $29.95 (available only in white).